I do recall this happening when I was getting off of Zoloft, many years ago, it did go away once I was fully weaned off, and my depression had gone in remission.
I also had this happen briefly when titrating up on my dosage of Celexa, I called it the "mild jerks", I say mild cause they only would happen once in awhile, not even enough to get concerned over, most of us without taking any meds will have the body jerk sometimes, ever get that feeling right before you go into a full sleep? It is normal. But with certain meds, it is always important to report to your doc, either the meds can be changed or adjusted, dosage wise.
I am glad you are taking this up with your doc, that is the best thing to do, and I wish you luck .
Drop back and chat here anytime, let us know how you are doing, or just talk, okay?

Take care,
DE

In giving advice seek to help, not please your friend
SOLON